Optical properties of exciton and charged exciton in undoped ZnSe/BeTe type-Ⅱ quantum wells under high magnetic fields

Abstract

We report on the magnetic field (up to 53 T) dependence of photoluminescence (PL) spectra occurring as a spacially direct optical transition of the ZnSe layer in undoped ZnSe/BeTe/ZnSe type-II quantum structures at a low temperature (4.2 K). With magnetic field increasing, the PL intensity (IX) of exciton (X) shows an oscillation feature opposite to the PL intensity (IX－) of charged exciton (X－). As IX- increases, IX decreases, but as IX－ decreases, IX increases. In all fields, the oscillation behaviour shows a periodic change approximately with magnetic field interval. The results are attributed to the periodic resonance of the Fermi level with the Landau level, which results in the modulation of the density of states of the 2DEG system at the Fermi energy.